Gear grinder



I 1,639,471 l 1927 H. e. SHAFER GEAR GRINDER Filed April 25, 1924 2 Sheets-Sheet 1 INVENTOR.

ATTORNEYS 16, 1927' H. G. SHAFER GEAR GRINDER Filed Aprii 25,. 1924 *2 Sheets-Sheet z INVENTOR. I Harvey 61'. Shafer,

A TTORNEYJ Illllll I 6 It is one of the objects of Patented Aug. 16,1927

UNITED STATES G. SEAFER, 'OF'INDIANAPOLIS, INDIANA GEAR GRINDER.

Application fled April 25, 1924. Serial No. 708,888;

My invention relates to improvements in grinding machines and particularly to grinding machines adapted for grinding gears, pinions, and the like. i

my invention to provide a machine of the above type which shall consist of relatively few parts and which shall permit the ready mounting'of the master gear and the gear blank for grinding purposes and provide means for properly associating the blank with the grinder wheel.

For the pur ose of disclosing my invention I have lllustrated' one embodiment thereof in the accompanying drawings in which,

Fig. 1 is a plan view of a'machine embodymg my invention; 1

Fig. 2 is an enlarged plan view of the and the guiding means;

Fig. 3 is a detail sectional View showing the relation of the parts;

Fig. 4 is a plan'view of a modification;

I Fig. 5 is a detail view showing one means of aligning the blank with the master gear, and

Fig. 6 is a detail section showing one means of mounting one type of gear in position. j

In the embodiment of the invention illustrated, I provide a universal grinder of the commercial type'having a bed 1 provided with a head 2 providing a universal mount-- ing for the grinding wheel 3 which is preferably removably mounted upon a rotatable shaft 4 and which, due to the construction .of the head, may be adjusted to'various angles.

Mounted upon the bed 1 is a bed plate'5 also adjustable relatively to the head 2 and provided with a longitudinally extending locking slot 6. Mounted upon this bed plate 5 is aguide plate 7 which, at opposite ends at the rear, is provided with slots 8 adapted to receive bolts- 9 mounted in the slots 6, which boltsare arranged to securely clamp the guide plate 7 in position upon the bed plate 5 and in proper relation to the grinding wheel 3. This guide plate 7 at the edge adjacent the grinding wheel, is provided with a rack 10 and the rack and guide plate are throated as at 11 to accommodate the grinding'wheel so that the grinding edge, or face, of the supporting table for'the gear to be ground wheel may be properly related to the teeth of the rack.

The. gear blank and master gear are adapted to be clamped together to form a 'single unitary structure which may be read ily slid over the face of the guide plate and to this end I provide a base member 12 having a central stud 13 adapted to receive the master gear 14. This stud, at its upper end, has a reduced extension 15 which receives a bushing 16 capable of receivin the ear blank 17. The shoulder 18 on t e bus ing 16, on its under face, rests on the top of the master gear and receives on its upper face,

pin 20 threaded at its upper. end to receive a set nut 21 which may be screwed down upon the clamping plate for locking the various parts together.

The rack 10 is mounted above a guide shoulder 22, the face 23 of which is in the plane of the pitch line of the rack and the base member 12 is cylindrical in form having its vertical face 24 in the plane of the pitch line of the master gear.

--In operation, the unit including the master gear and blank is slidable by the operator on. the guide plate 7, the bottom face of the base 12 and the upper face of the guide plate 7 being ground accurately. The operator moves -the unit forward until the vertical face 24 engages the face 23 which will engage the teeth of the master gear with the teeth of the rack and, by a slight rotatable movement, the gear is rolled along the rack bringing'a tooth to be ground into engagement with the grinding wheel. As soon as the grinding operation on this tooth is completed the unit is moved transversely of the table to back it away from the rack and wheel and by drawing the unit forward the process may be repeated for the next tooth until all of the teeth have been suitably ground.

In -Fig. 4 I have illustrated a modification whereinthe grinding wheel is so arranged with relation tothe parts that the adjacent faces of two teeth may be ground at the same time. In this construction the grinding Wheel 3 operates in a' straight throat 11 in a member 10 having a gear face 23, the

parts 22', 7', 19', 20', 21', 17', 12. and 24'. being the same as in the structure illustrated in Figs. 1 to 3.

In Fig. 5 I have shown a structure whereby the master gear and the blank may be properly aligned. This comprises a block 25 having an overhanging shoulder 26 through which vertically extends a pin 27 sion gear having a hollow spindle and so constructed that the same can not be readily clamped in in Fig. 4.

' In this structure the base member 12" is provided with a hollow stud 28 adapted to receive the master gear 29. The hub of this gear extends above the stud 28 and is provided with oppositely disposed openings to receive the spindle 30 of an eccentric 31. A collet 32 provided with an annular shoul position by the means illustrated der 33 is arranged to fit within the hub of the master gear and this collet at its upper end is split as at 34: and adapted to receive the hollow hub of the blank 35. A semispherical head 36 fits within the upper end of the collet and is provided with a stem 37 arranged to extend through the collet and provided at its lower end with an opening in which the eccentric 31 is adapted to fit.

In assembly the master gear is first placed on the stud 29, after which the collet 32 is placed in position and the eccentric passed through the opening in the bottom of the stem 37, the spindle thereof operating in the openings in the hub of the master gear.

The blank is then placed upon the upper end of the collet and by rotating the eccentric, the head 36 is drawn down into the collet, thereby spreading the split head into engagement with the interiorof the hub and the blank 35 and securely locking the parts together.

m In the specification I have referred to the gear blank. It will be understood that this structure contemplates either a blank from which a gear may be enter a structure wherein the teeth have been roughed out andare adapted to be finished by my invention. In the drawings I have illustrated a form wherein the teeth have been roughed out.

While I have shown in the drawings and described the rack 10 as having a throat formed therein for the accommodation of the grinding wheel it is obvious that the gears may be arranged on a spindle which will support them sufiiciently elevated above the bed so that the grinding wheel may come in contact therewith without the necessity of a throat in the rack.

I claim as my invention:

1. In a gear grinding machine, the combination with a grinding wheel and a bed, of a guide plate having a rack, means for supporting the plate on said bed with the rack in predetermined relation to the grinding wheel, and a blank supporting unit including a base, a master gear on said base and means "for securing the blank on the base in predetermined relation to the master gear, said base being slidable on the guide plate in two directions at an angle to one another to permit the master gear to be moved laterally into andout of engagement with the rack and be rolled on said rack.

2. In a gear grinding machine the combination with a grinding Wheel and a bed, of a guide plate having a rack, means for supporting the plate on said. bed with the rack in predetermined relation to the grinding wheel, and a blank supporting unit including a circular base, a stem. extending .vertically from said base, a master gear mounted on said stem and means for securing the blank on said stem in predetermined relation to the master gear. said base being freely slidable on said guide plate in two directions at an angle to one another to permit the master gear to be moved laterally into and out of engagement with the rack and to be rolled on said rack. I

3. In a grinding machine,- the combinat1on w1th a grlnding wheel and a bed, of a gu de plate having a rack, means for supporting the plate on said bed with the rack in predetermined relation to the rindin wheel, a gauge coincident with t e pitc line of the teeth of said rack and a blank supporting unit including a base, a master gear a means for securing the blank on the base in predetermined relation to the master g ar, said base having a gauge face colncid t with the pitch line of the teeth of th master gear and arranged to co-operate with the rack gauge and said base being freely slidable on the guide plate to permit the master gear to be moved into and out of engagement with the rack and to be rolled on said rack.

4.. In a grinding machine, the" combination with a grinding wheel, of a rack,- means for supporting said rack in predetermined relation to the grinding wheel, a gauge coincident with the pitch line of the teeth of said rack, a blank support including a gauge member and a master gear, .sald gauge member having a gauging face coincident with the pitch line of the master gear, said master gear being arran d to have a rolling movement .on said ran and said gauges being arranged to co-operate during said p0 rolling movement to determine the pitch line of the gear to be ground.

5. In a grinding machine, the combina tion with a grinding wheel, of a rack mounted in predetermined relation to the wheel, means for supporting a gear b including a master. gear, and a pitch line 10 gauge eo-operating with said rack and sup- In witness whereof, I, Hum G. Siam, have hereunto set my hand at Indianapolis,

Indiana, this 2nd day of April, A. D. one 1 thousand nine hundred and twenty-four.

HARVEY G. SHAFER. 

